Question

M is the midpoint of AB. Find the coordinates of B given A(2,-1) and M(8,3).

Answer 1

Use the mid-point formula:
\[M=(\frac{ {x_{1}+x_{2}} }{ 2 },\frac{ y_{1}+y_{2} }{ 2 })\]
Plug in what you have, which is Midpoint(8,3) and A(2,-1)
Solve for missing parts, which is point B
\[8=\frac{ 2+x }{ 2}, 3=\frac{ -1+y }{ 2 }\]
\[(2)8=(\frac{ 2+x }{ 2})2, (2)3=(\frac{ -1+y }{ 2 })2\]
\[16=2+x, 6=-1+y\]
-2 -2 , +1 +1
x = 18 , y = 7
B(18,7)

Answer 2

Thank you very much i just needed the midpoint formula thanks now i can check my work. :)

Answer 3

Yup, good luck!